Hybrid automobiles and electric automobiles driven by the driving force of a motor are widely used. These motor driven vehicles have a booster converter for boosting a battery voltage and outputting the boosted voltage to a motor drive circuit.
The booster converter has a booster coil and a switching circuit for switching current flowing to the booster coil. The booster coil generates an induced electromotive force by switching of the current. The booster converter outputs to the motor drive circuit a boosted voltage where the induced electromotive force has been added to an input voltage. As a result, the booster converter can output a voltage higher than the battery voltage to the motor drive circuit.